A lightning detector is a system which can detect the presence of incoming thunder storms with lightning activities. Lightning is the result of flowing current due to the electrostatic charge separation in clouds. Typically this current is massive and can flow from the cloud to the ground or inside the cloud. The current flow generates an electromagnetic field.
From an electromagnetic point of view, lightning flashes produce very wide band signals. To monitor such a wide band frequency range with portable devices is very challenging. Lightning is a complex phenomenon made up of several different events: breakdown, return stroke, in-cloud activities and subsequent stroke. Scientific literature establishes that by analyzing the phenomenon using a narrow band system many details could be lost and it would no longer be possible to distinguish between the basic elementary processes which constitute lightning. Nevertheless, this approach is suitable for detecting lightning itself.
The subject application focuses on a narrow band radio frequency receiver which is to be used in a lightning detector. The receiver scans around a few hundred kilohertz up to a couple of megahertz as the central frequency. The challenge that comes with this lightning detection involves so-called manmade disturbers. Manmade disturbers can be classified in three different categories, namely low-energy signals, square envelope signals and continuous jamming noise.
There are known lightning detectors which evaluate the pattern of the incoming signal and subsequently perform an assessment. For this the received signal is digitized using, for instance, an analog-to-digital converter. An external unit then generates a histogram out of the sampled signal. These known systems are usually implemented in a digital signal processor, DSP, with high computing power. Power consumption of such DSP is in the range of 10 to 100 milliampere. Besides this, the solution is quite expensive.
One object consists of providing a circuit arrangement and method for disturber detection which enables reduced power consumption and an implementation at low cost.